Dynamics of microfilariae of Onchocerca volvulus over the first 72 hours after treatment with ivermectin
Richards, F.O.; Zea Flores, R.; Duke, B.O.
Tropical Medicine and Parasitology Official Organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit 40(3): 299-303
1989
ISSN/ISBN: 0177-2392 PMID: 2617037 Document Number: 339711
Changes in microfilaria (mf) densities in skin, blood and urine were followed over 72 hours in 8 Guatemalan patients who received ivermectin (150 micro g/kg po in a single dose). After an initial increase at 6 hours, the significance of which is not clear, mf densities in skin snips decreased rapidly to reach 13% of their pre-treatment level by 48 h and then fell much more slowly over the next 24-hour period. The fall in mf concentrations is thought to be mainly a result of movement away from the subepidermal layer. In contrast to what happens after DEC, it was not accompanied by any marked wave of microfilaraemia or microfilaruria, nor by the appearance of a papular rash, although brawny oedema of the skin sometimes developed. Reactions that occurred after ivermectin could not be correlated with the initial density of microfiladermia. It is hypothesized that the movement of mfs may be (1) into the deeper layers of the dermal collagen, (2) the subcutaneous fat, or (3) the lymphatic system.AS Changes in O. volvulus microfilaria (mf) densities in skin, blood and urine were followed over 72 h in 8 Guatemalan patients who received ivermectin (150 mcg/kg orally in a single dose). After an initial increase at 6 h, the significance of which is not clear, mf densities in skin snips decreased rapidly to reach 13% of their pre-treatment level by 48 h and then fell much more slowly over the next 24-h period. The fall in mf concentrations is thought to be mainly a result of movement away from the subepidermal layer. In contrast to what happens after DEC, it was not accompanied by any marked wave of microfilaraemia or microfilaruria, nor by the appearance of a papular rash, although brawny oedema of the skin sometimes developed. Reactions that occurred after ivermectin could not be correlated with the initial density of microfiladermia. It is hypothesized that the movement of mfs may be into the deeper layers of the dermal collagen, the subcutaneous fat, or the lymphatic system.